Mini-intronic Plasmid Vectors for Stable Transgene Expression
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for long-term expression of transgenes face challenges such as transgene silencing and aberrant expression due to integration into the host genome, and the production of minicircle vectors is a multistep, time-consuming process.
Innovation Solution
The development of mini-intronic plasmid vectors (MIP vectors) that incorporate a bacterial origin of replication and selectable marker within an intron, allowing for persistent and high-level expression of transgenes without integration into the host genome, while simplifying the production process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If traditional plasmid vectors are used for long-term transgene expression, then the production process is simple and fast, but the transgenes undergo silencing and aberrant expression due to integration into the host genome
Solution Approach 1:
The invention extracts and removes the problematic bacterial backbone sequences (origin of replication, selectable markers) from the plasmid vector, retaining only the essential expression cassette. This extraction eliminates the silencing and aberrant expression issues caused by genomic integration of complete plasmids while maintaining the simplicity of plasmid-based production methods.
Solution Approach 2:
The vector is segmented into two functional parts: a minimal expression cassette containing only the promoter, transgene, and polyadenylation signal, and the bacterial backbone sequences. This segmentation allows the expression cassette to function independently without the harmful effects of complete plasmid integration, while the backbone can be separately handled during production.
2Reliability
If minicircle vectors are used for long-term transgene expression, then transgene expression stability is improved, but the production process becomes multistep and time-consuming
Solution Approach 1:
The invention creates a simplified copy or variant of the minicircle vector concept, using a plasmid backbone that retains essential replication and selection functions while removing only the problematic sequences. This copying approach maintains the expression stability benefits of minicircles without requiring the complex multistep production process.
Solution Approach 2:
Instead of starting with a minicircle vector and adding back bacterial elements (the conventional approach), the invention inverts the process by starting with a complete plasmid and removing problematic elements. This inversion simplifies the production process while achieving similar expression stability outcomes.
3Duration of action of stationary object
If minicircle vectors are used for long-term transgene expression, then transgene silencing is avoided, but the production time increases significantly
Solution Approach 1:
The invention performs preliminary removal of silencing-prone bacterial sequences during the plasmid construction stage, before vector production and delivery. This preliminary action ensures long-term expression stability is built into the vector design itself, eliminating the need for time-consuming post-production purification steps required by traditional minicircle methods.
Data Source
AI summary
Compositions and methods are provided for achieving persistent, high level expression of transgenes in vitro and in vivo. Aspects of the invention include vectors comprising an intronic cassette that comprises plasmid elements, and methods that rely on the use of vectors comprising an intronic cassette that comprises plasmid elements. These compositions and methods find use in many applications, including therapeutic applications such as in gene therapy; synthesis applications such as in the synthesis of peptides, proteins, and RNAs, e.g. for research or therapeutic purposes; and research applications, such as in the production of transgenic cells and animals. In addition, reagents, devices and kits thereof that find use in making the subject compositions and practicing the subject methods are provided.